Method for obtaining value-determining contents from foods

Abstract

The invention relates to a method for obtaining value-determining contents, such as flavouring substances, vitamins, and polyphenols, from foods (13), having the following steps: a) providing a food (13), b) adding a plant oil (15) as an extractant, c) grinding the food (13) and the plant oil (15) into a mash (21), and d) separating the mash into an extraction phase, which is an oil phase (25), and a solid phase (29) as a raffinate phase. The food (13) and the plant oil (19) are ground very finely, said grinding process being defined in that the food (13) together with the plant oil (15) is ground until the oil phase (25) has an average particle size of less than 300 μm, preferably less than 100 μm, particularly preferably less than 20 μm.

Claims

1. A method for obtaining ingredients from a foodstuff, the method comprising: (a) providing the foodstuff; (b) adding an extractant; (c) grinding the foodstuff and the extractant into a mash; and (d) separating the mash into an extraction phase and a raffinate phase, wherein the extraction phase is an oil phase and the raffinate phase is a solid phase, wherein the foodstuff with the extractant is ultra-finely ground, the ultra-fine grinding being defined in that the foodstuff with the extractant is ground until the oil phase has an average particle size of less than 100 μm, and in that the mash is separated by a three-phase separator into the solid phase, the oil phase for obtaining an essential oil, and an aqueous phase, wherein the oil phase is freed of sediments and suspended matter in a 2-phase separator.

2. The method according to claim 1, wherein the extractant is a vegetable oil.

3. The method according to claim 1, wherein the extractant is a salt solution or a sugar solution.

4. The method according to claim 1, wherein the extractant is a mixture of two or three of the vegetable oil, the salt solution and the sugar solution.

5. The method according to claim 1, further comprising adding an additive having an antioxidant effect to the extractant, wherein the additive is vitamin C, vinegar, oxalic acid or tocopherol.

6. The method according to claim 1, wherein after the ultra-fine grinding—the oil phase is created from the mash in which fat-soluble ingredients comprising flavouring substances, vitamins and polyphenols are extracted, the aqueous phase is created in which germs and other water-soluble substances are enriched and the solid phase is created in which the solid residues remain.

7. The method according to claim 1, wherein the ultra-fine grinding is carried out in a toothed colloid mill, the grinding gap is less than 0.1 mm.

8. The method according to claim 1, wherein the ultra-fine grinding is carried out in two stages a first grinding stage and a second grinding stage.

9. The method according to claim 8, wherein the first grinding stage is performed in a perforated disc mill and the second grinding stage is performed in a toothed colloid mill.

10. The method according to claim 1, wherein the ultra-fine grinding is carried out at room temperature.

11. The method according to claim 1, wherein the foodstuff is supplied fresh or immediately after harvesting.

12. The method according to claim 1, wherein the oil phase is degassed and dewatered by a vacuum vent.

13. The method according to claim 1, wherein the temperature of the mash increases by 10 to 20° C. during ultra-fine grinding.

14. The method according to claim 1, wherein a reduction of the bacterial count and/or microbiological stabilisation is achieved by the ultra-fine grinding in the oil phase.

15. The method according to claim 1, wherein the formation and separation of the aqueous phase and/or the ultra-fine grinding reduces the bacterial count in the oil phase compared with the bacterial count of the oil phase in 2-phase separation.

16. The method according to claim 1, wherein the concentration of presumptive Bacillus cereus in the oil phase is reduced to less than 100 colony-forming units/g and the concentration of Enterobacteriaceae to less than 10 colony-forming units/g by formation and separation of the aqueous phase.

17. The method according to claim 1, wherein the method extracts at least 90% of fat-soluble vitamins from the foodstuff into the oil phase.

Description

(1) Further advantages and features result from the following description of an embodiment of the invention with reference to the schematic illustrations.

(2) FIG. 1: a flowchart of a method for obtaining valuable substances such as flavouring substances and vitamins;

(3) FIG. 2: a diagram which illustrates the decrease of the total bacterial count;

(4) FIG. 3: a graph of particle size distribution with mint as raw material,

(5) FIG. 4: a graph of particle size distribution with onion as raw material and

(6) FIG. 5: a flowchart of a second embodiment of the method for the obtaining of valuable substances such as flavouring substances and vitamins.

(7) FIG. 1 shows a flowchart of a method for obtaining valuable substances, in particular flavouring substances, vitamins and polyphenols from fresh foodstuff. In particular, freshly harvested plants suitable for consumption, such as herbs, spices or vegetables, are processed as raw materials. Fruits are also conceivable as raw materials. It is particularly preferred if the plants are processed as freshly as possible in order to extract as many pure flavours as possible. Because through storage and preservation, plants inevitably lose their fresh and very own aroma. The time between harvesting the plant and processing should therefore be kept as short as possible. The plants processed as raw materials are marked with the reference numeral 13.

(8) The plants 13 are washed and, together with a vegetable oil 15, subjected to an ultra-fine grinding process. If the plants 13 have a very low water content, water can optionally be added. The vegetable oil 15 is preferably a vegetable oil, which contains predominantly long-chain fatty acids, so that an undesired rancidity of the vegetable oil is prevented. For example, sunflower oil or rapeseed oil can be used. Within the scope of this application, ultra-fine grinding is preferably understood as grinding in a mill which leads to an average particle size of less than 300 μm in the oil phase. Within the scope of this patent application, the average particle size is preferably defined by all particle sizes contributing according to their volume fraction in the collective. The average particle size in the interval is weighted with the corresponding volume portion and all these weighted values are averaged arithmetically. According to a variant, the particle size can be determined by sieving, filtering or by laser photometer. Ultra-fine grinding is preferably carried out in two stages in order to achieve the desired particle size distribution (PGV) as quickly and reliably as possible. For example, the first grinding stage can be carried out in a perforated disc mill 17 and the second grinding stage can be carried out in a toothed coloid mill 19. The toothed colloid mill 19 is preferably equipped with a grinding gap of less than 0.1 mm in order to achieve the ultra-fine grinding. The size of the grinding gap must be adapted to the plants to be ground. Therefore, the size of the grinding gap can be other than 0.1 mm. Ultra-fine grinding exerts shear/impact and density stress on the microorganisms introduced, which leads to a reduction in living microorganisms.

(9) Preferably the vegetable oil 15 is used at room temperature, since tests with a vegetable oil feed at 80° C. did not bring any improvements in the stabilization of microbiology. If microbiology is stable, the entirety of germs can no longer multiply, which is important for a sufficient shelf life. These experiments relating to microbiology are discussed in more detail below. The thermal inactivation of various enzymes leads to the preservation of value determining ingredients such as chlorophyll.

(10) The intermediate product that leaves the ultra-fine grinding stage is called mash 21. Due to the ultra-fine grinding, it is surprisingly possible to separate the mash 21 into three phases. Rather, an emulsion formation would have to be expected. The three phases are separated by a 3-phase separator in the form of a three-phase decanter centrifuge 23. The mash 21 can be separated into an oil phase 25, an aqueous phase 27 and a solid phase 29.

(11) In oil phase 25, the flavouring substances and essences of the starting material are extracted. The analysis of microbiology in oil phase 25 leads to surprisingly low concentrations of microorganisms or germs (see below). This is due to shear/impact and density stress during ultra-fine grinding and the absence of water and oxygen. Since neither water nor oxygen is present in oil phase 25, the number of microorganisms remaining in oil phase 25 remains stable, even if the end product is stored for a longer period of time.

(12) In the oil phase 25 the fat-soluble ingredients of the raw material accumulate. Fat-soluble ingredients include flavouring substances and vitamins. Flavouring substances and vitamins, if present in the raw material, are particularly highly concentrated in the final product available from the oil phase 25. Polyphenols, although mainly enriched in the aqueous phase, are also present in the oil phase. The end product is therefore called essential oil.

(13) The formation and separation of aqueous phase 27 means that germs can accumulate in the aqueous phase and are therefore depleted in the oil phase.

(14) All ingredients of the starting material remain in the solid phase, which neither pass into the oil phase 25 nor into the aqueous phase 27.

(15) The next method steps serve to optimize the quality of the final product (essential oil).

(16) In the next method step, the oil phase 25 is separated from water residues and water-soluble volatile components and water-soluble flavouring substances in a vacuum deaerator 31. The separated aroma phase 33 can be used (preferably after further processing, for example by distillation, a cold trap or membrane process) for flavouring other products.

(17) In the next method step, heat treatment 35 and subsequent cooling 37 of the oil phase can be provided so that the oil phase can be thermally treated if required.

(18) A sediment formed in the oil phase 25 can be separated in a centrifuge 39.

(19) The oil phase 25 can also be homogenized.

(20) It is preferred if the end product is filled into a filling station in a bag-in-box packaging. In such packaging, contact of the product remaining in the bag with atmospheric oxygen is prevented even after a product has been removed. This makes the end product particularly durable.

(21) The end product is rich in valuable substances such as flavouring substances, vitamins and polyphenols and is therefore called essential oil 41 or plant essence.

(22) Microbiological stabilization in oil phase 25 is achieved by ultra-fine grinding and separation of the aqueous phase. In an embodiment, mint was processed as the starting material using the process according to the invention. The table below shows that the colony-forming units/g (CFU/g) were significantly reduced after ultra-fine grinding. Since the microbiological stability of mash 21 is already due to the microbiological reduction of the bacterial count, it is also conceivable to use the mash as a further end product as a highly aromatic paste 43. By separating the oil phase 25 from the aqueous phase 27, the aerobic germs in particular could be greatly reduced once again.

(23) TABLE-US-00001 Germ load Germ load Germ load Raw material Mash Oil phase Germ [CFU/g] [CFU/g) [CFU/g] Mint Aerobic germs 72,000,000 280,000 440 Total germ number Presumptive 200 <100 <100 Bacillus cereus Enterobacteriaceae 2,200 60 <10 Escherichia coli <10 <10 <10 Pseudomonas sp. — — — Coagulase pos. <100 <100 <100 Staph.

(24) A test with leek has shown that the use of vegetable oil at room temperature did not lead to a change in the bacterial count in the oil phase compared to that at 80° C. This has the advantage that the method according to the invention can be carried out particularly gently at room temperature without increasing the bacterial count in the end product. Preference is given to keeping the process temperature low during ultra-fine grinding, as the temperature increases by a maximum of 15° C. during grinding.

(25) TABLE-US-00002 Germ load Germ load Oil phase Germ load Raw material 80° C. Oil phase RT Germ [CFU/g] [CFU/g) [CFU/g] Leek Aerobic germs 1,000,000 <10 <10 Total germ number Presumptive <100 <100 <100 Bacillus cereus Enterobacteriaceae 65,000 <10 <10 Pseudomonas sp. >15,000 <100 <100 Coagulase pos. <100 <100 <100 Staph.

(26) The diagram in FIG. 2 illustrates the reduction of the total bacterial count with onion, mint or parsley as raw material. It is shown that not only the ultra-fine grinding has an influence on the reduction of the total bacterial count. To almost the same extent, the total number of bacteria can also be reduced by using the three-phase decanter 23. A large proportion of the germs can accumulate in the aqueous phase 27, whereby the number of germs in the oil phase can be brought into the range of 100 colony-forming units per gram.

(27) An analysis of the particle size distribution of oil phase 25 for mint and onion as raw materials has the graphs according to FIGS. 3 and 4 as a result. On the abscissa the particle diameters are plotted logarithmically in μm and on the ordinate the volume proportions are plotted linearly in %. The table below lists the diameter distributions, indicating how many vol % of the particles have a smaller diameter than the values given:

(28) TABLE-US-00003 Raw material D(10%) D(50%) D(90%) Mint 18 μm  83 μm 273 μm Onion 14 μm 117 μm 353 μm

(29) The median value X.sub.50.3 is less than 300 μm in the oil phase 25 of the process according to the invention, preferably less than 100 μm and especially preferably less than 20 μm.

(30) The modal value X.sub.h.3 is less than 300 μm in the oil phase 25 of the process according to the invention, preferably less than 100 μm and especially preferably less than 20 μm.

(31) The sufficient comminution of the raw material by the ultra-fine grinding makes it possible to extract the value-determining ingredients, in particular flavouring substances and vitamins, with high efficiency. As already mentioned, ultra-fine grinding is also essential for the necessary reduction of bacterial counts in the oil phase 25. The process control must therefore be selected in such a way that an average PGD of less than 300 μm in the oil phase is reliably achieved. In this way, the desired effects on the reduction of bacterial counts and extraction efficiency can be achieved.

(32) FIG. 5 shows a flow chart of a second type of process for obtaining value-determining constituents. As an alternative to a vegetable oil as extractant, a concentrated salt solution 45 or a concentrated sugar solution 47 can also be used as extractant. It is also conceivable that the extractant is a mixture of a vegetable oil and a concentrated salt solution or a mixture of a vegetable oil and a concentrated sugar solution or a mixture of vegetable oil, sugar and salt solution.

(33) The fresh foodstuff 13 is, as already in the first embodiment, finely ground with the extractant or the mixture of extractants, preferably in a first grinding stage 17 and in a second grinding stage 19.

(34) The concentration of the sugar solution is between 40 and 60% (m/m) and preferably between 50 and 65% (m/m). The concentration of the salt solution is between 10 and 30% (m/m) and preferably between 15 and 25% (m/m). These concentrations of sugar and salt solution, which correspond at most to the saturation concentration, lead to an antimicrobial effect, since the concentrated salt or sugar solution leads to a driving concentration gradient at the cell membranes of the microorganisms. The microorganisms and germs are inevitably introduced by foodstuff 13, especially fresh food. The water contained in the cells of micro-organisms and germs tries to get into the solution in order to balance the difference in concentration of sugar or salt. The cells burst and the concentration of living microorganisms or germs is reduced in mash 21. Enzymes are also inactivated.

(35) After ultra-fine grinding, the mash 21, as in the first embodiment, is separated in a three-phase separator, for example in the form of a three-phase decanter centrifuge 23. Aqueous phase 27, which in addition to the dissolved salt or sugar also contains valuable substances, can be subjected to drying 49. The salt or sugar crystallises as a result of the drying process. The solids formed are enriched with valuable substances extracted into the aqueous phase. For example, an “essential salt” 53 or an “essential sugar” 51 can be produced, which are enriched with the valuable substance. The oil phase 25 produced in the three-phase decanter centrifuge 23 can be used as essential oil 41 after treatment 55, as already described in the first embodiment. In the second embodiment, the resulting oil phase 25 comes from the foodstuff.

(36) In addition to the extractant, an active substance with an antioxidant effect can also be added to the foodstuff. This further improves the shelf life of the end products. The active substance is at least partially used up in mash 21 to ensure the antioxidant effect. The active substance may be vitamin C, vinegar, oxalic acid or tocopherol, for example, or may be contained in rosemary. Rhubarb juice or rhubarb juice concentrate is conceivable as a source of oxalic acid. The oxaloacetic acid formed from vinegar and oxalic acid can cause enzyme inhibition in mash 21. The oxaloacetic acid, which is not used up, can be precipitated with calcium to neutralize the acid effect.

LEGEND

(37) 13 starting material, raw material, fresh plants 15 vegetable oil 17 perforated disc mill, first grinding stage 19 toothed colloid mill, second grinding stage 21 mash 23 three-phase decanter centrifuge 25 oil phase 27 aqueous phase 29 solid phase 31 vacuum deaerator 33 aroma phase 35 heat treatment 37 cooling 39 centrifuge, 2 phase separator 41 essential oil 43 paste 45 salt solution 47 sugar solution 49 drying 51 essential sugar 53 essential salt 55 preparation